Method of manufacturing a thin film transistor substrate and stripping composition

ABSTRACT

A method of manufacturing a thin film transistor substrate includes forming a transistor thin layer pattern, forming a protecting layer, forming a photoresist film, forming a pixel electrode and a conductive layer that are separated from each other, stripping a photoresist pattern to remove the conductive layer using a stripping composition and dissolving the conductive layer. The method of manufacturing a thin film transistor substrate is capable of improving an efficiency of manufacturing process of the thin film transistor substrate. In addition, the stripping composition is recycled.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 11/215,140 filed on Aug. 30, 2005 and issued as U.S. Pat. No.7,300,827 on Nov. 27, 2007, which claims priority to Korean PatentApplication No. 2004-68791 filed on Aug. 30, 2004, and Korean PatentApplication No. 2005-44153 filed on May 25, 2005, and all the benefitsaccruing therefrom under 35 U.S.C. §119 the contents of which are hereinincorporated by reference in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of manufacturing a thin filmtransistor substrate and a stripping composition. More particularly, thepresent invention relates to a method of manufacturing a thin filmtransistor substrate capable of simplifying a manufacturing process ofthe thin film transistor substrate and a stripping composition employedfor the manufacturing process of the thin film transistor substrate.

2. Description of the Related Art

In general, a display device includes a cathode ray tube type (CRT)display (CRT) device, a liquid crystal display (LCD) device, a plasmadisplay panel (PDP) device, and an organic light emitting display (OLED)device.

Most of the display devices, except for the CRT device, include a thinfilm transistor substrate having a thin film transistor so as to displayimages.

In order to simplify the manufacturing process of the thin filmtransistor substrate to reduce a manufacturing cost, novel technologieshave been rapidly developed.

SUMMARY OF THE INVENTION

The present invention provides an exemplary embodiment of a method ofmanufacturing a thin film transistor substrate capable of simplifying amanufacturing process of the thin film transistor substrate.

The present invention also provides an exemplary embodiment of astripping composition that is used for the manufacturing process of thethin film transistor and is reusable.

In exemplary embodiments of a method of manufacturing a thin filmtransistor substrate, a transistor thin layer pattern is disposed on asubstrate. A protecting layer is disposed on the transistor thin layerpattern. A photoresist film is disposed on the protecting layer. Thephotoresist film forms a photoresist pattern on the substrate by aphotolithography process. An undercut is generated at a lower portion ofthe photoresist pattern by the photolithography process. A pixel area isformed on a portion of the substrate by removing the photoresist film. Aconductive material is deposited on the photoresist pattern. Theconductive material is deposited on the photoresist pattern to form aconductive layer, and the conductive material is deposited on the pixelarea to form a pixel electrode. A stripping composition is applied ontothe pixel electrode and the photoresist pattern to strip the photoresistpattern, so that the conductive layer formed on the photoresist patternis separated from the substrate. A used stripping composition containingthe conductive layer separated from the substrate is collected andstored in a storage tank. The conductive layer separated from thesubstrate is completely dissolved in the used stripping composition.

In another exemplary embodiment, the stripping composition includes botha stripping agent for stripping the photoresist and a stripping additivefor dissolving the conductive layer.

In another exemplary embodiment, a stripping composition includes astripping agent for stripping a photoresist and a stripping additive forstripping a conductive layer. The stripping agent for stripping thephotoresist includes about 20 percent by weight to about 40 percent byweight of an amine-based compound, about 20 percent by weight to about50 percent by weight of a protonated glycol-based compound and about 20percent by weight to about 40 percent by weight of a deprotonatedmultipolar compound. The stripping additive for stripping the conductivelayer includes about 0.5 percent by weight to about 3 percent by weightof a thiol-based compound.

In another exemplary embodiment, the thiol-based compound may include athio benzoic acid or thiol acid.

In another exemplary embodiment of the method of manufacturing a thinfilm transistor substrate, the number of masks may decrease, so that themanufacturing process of the thin film transistor may be simplified.Additionally, the stripping composition used for manufacturing the thinfilm transistor substrate may dissolve the photoresist film, andfurthermore the stripping composition may completely dissolve theconductive layer after the photoresist film is dissolved.Advantageously, the stripping composition according to the presentinvention may be recycled.

In another exemplary embodiment of the method of manufacturing a thinfilm transistor substrate, a gate line and gate electrode are formed onthe substrate substantially perpendicular to each other. A gateinsulating layer is formed on the substrate covering the gate line andgate electrode. An amorphous silicon pattern and an n⁺ amorphous siliconpattern are formed on the gate insulating layer. A date line, sourceelectrode and drain electrode are formed on the substrate. The sourceelectrode and the drain electrode are electrically connected to the n⁺amorphous silicon pattern. The forming of the gate line, the gateelectrode, the amorphouse silicon pattern, the n⁺ amorphous siliconpattern, the date line, the source electrode and the drain electrodeuses multiple masks.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other advantages of the present invention will becomereadily apparent by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIG. 1 is a plan view illustrating an exemplary embodiment of a gateline formed on a substrate by an exemplary embodiment of a method ofmanufacturing a thin film transistor substrate according to the presentinvention;

FIG. 2 is a cross-sectional view taken along line I-I′ in FIG. 1;

FIG. 3 is a plan view of an exemplary embodiment of a channel layerformed on the exemplary embodiment of the gate line in FIG. 1;

FIG. 4 is a cross-sectional view taken along line II-II′ in FIG. 3;

FIG. 5 is a plan view of an exemplary embodiment of source and drainelectrodes electrically connected to the exemplary embodiments of an n⁺amorphous silicon pattern in FIG. 3;

FIG. 6 is a cross-sectional view taken along line III-III′ in FIG. 5;

FIG. 7 is a plan view of an exemplary embodiment of a photoresistpattern formed on an exemplary embodiment of a protecting layer;

FIG. 8 is a cross-sectional view taken along line IV-IV′ in FIG. 7;

FIG. 9 is an enlarged view of an exemplary embodiment of portion ‘A’ inFIG. 8;

FIG. 10 is a cross-sectional view of an exemplary embodiment of atransparent conductive thin layer formed on the exemplary embodiment ofa substrate in FIG. 9;

FIG. 11 is a cross-sectional view of an exemplary embodiment of thesubstrate in FIG. 10 with a part of a photoresist pattern and aconductive layer removed according to an exemplary method of anembodiment of the invention;

FIG. 12 is a cross-sectional view of an exemplary embodiment of a thinfilm substrate in FIG. 11 without the photoresist pattern and theconductive layer;

FIG. 13A is a picture of a surface of a conductive layer dissolved by anexemplary embodiment of a stripping composition of Example 1;

FIG. 13B is a picture of a surface of a conductive layer dissolved by anexemplary embodiment of a stripping composition of Example 2; and

FIG. 13C is a picture of a surface of a conductive layer dissolved by anexemplary embodiment of a stripping composition of Example 3.

DETAILED DESCRIPTION OF THE INVENTION

The invention is described more fully hereinafter with reference to theaccompanying drawings, in which exemplary embodiments of the inventionare shown. This invention may, however, be embodied in many differentforms and should not be construed as limited to the exemplaryembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. In thedrawings, the size and relative sizes of layers and regions may beexaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to” or “coupled to” another element or layer, theelement or layer can be directly on, connected or coupled to anotherelement or layer or intervening elements or layers. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numbers refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third,etc., may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present invention.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper” and the like, may be used herein for ease of description todescribe the relationship of one element or feature to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation, in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below” or “beneath”other elements or features would then be oriented “above” the otherelements or features. Thus, the exemplary term “below” can encompassboth an orientation of above and below. The device may be otherwiseoriented (rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Embodiments of the invention are described herein with reference tocross-section illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of the invention. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments of the invention should not be construed aslimited to the particular shapes of regions illustrated herein but areto include deviations in shapes that result, for example, frommanufacturing.

For example, an implanted region illustrated as a rectangle will,typically, have rounded or curved features and/or a gradient of implantconcentration at its edges rather than a binary change from implanted tonon-implanted region. Likewise, a buried region formed by implantationmay result in some implantation in the region between the buried regionand the surface through which the implantation takes place. Thus, theregions illustrated in the figures are schematic in nature and theirshapes are not intended to illustrate the actual shape of a region of adevice and are not intended to limit the scope of the invention.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

An Exemplary Embodiment of a Method of Manufacturing a Thin FilmTransistor Substrate

FIG. 1 is a plan view of an exemplary embodiment of a gate line formedon a substrate by an exemplary embodiment of a method of manufacturing athin film transistor substrate according to an embodiment of the presentinvention. FIG. 2 is a cross-sectional view of an exemplary embodimentof the gate line taken along line I-I′ in FIG. 1.

Referring to FIGS. 1 and 2, a gate line 110 is formed on a substrate 100along a first direction, and a gate electrode 112 is formed on the gateline 110 extended along a second direction substantially perpendicularto the first direction. In exemplary embodiments, a conductive gate thinlayer entirely formed on the substrate 100 is patterned using a mask toform the gate line 110 and the gate electrode 112. In alternativeembodiments, the conductive gate thin layer may include, but is notlimited to, aluminum, an aluminum alloy, and the like, as well ascombinations including at least one of the foregoing.

A gate insulating layer 114 may be formed on the substrate 100 to coverthe gate line 110 and the gate electrode 112 as shown in the exemplaryembodiment of FIG. 2.

FIG. 3 is a plan view of an exemplary embodiment of a channel layerformed on the gate line in FIG. 1. FIG. 4 is a cross-sectional viewtaken along line II-II′ in FIG. 3.

Referring to FIGS. 3 and 4, an amorphous silicon thin layer and an n⁺amorphous silicon thin layer 120 may be sequentially formed on an upperface of the gate insulating layer 114. The amorphous silicon thin layerand the n⁺ amorphous silicon thin layer 120 may be patterned by aphotolithography process using a mask to form an amorphous siliconpattern 122 and an n⁺ amorphous silicon pattern 124 on the gateelectrode 112. The amorphous silicon pattern 122 may be formed on thegate insulating layer 114 corresponding to the gate electrode 112. Apair of the n⁺ amorphous silicon pattern 124 may be formed on an upperface of the amorphous silicon pattern 122. In the exemplary embodimentin FIG. 4, the n⁺ amorphous silicon patterns 124 may be spaced apartfrom each other.

FIG. 5 is a plan view of an exemplary embodiment of source and drainelectrodes electrically connected to the n⁺ amorphous silicon pattern inFIG. 3. FIG. 6 is a cross-sectional view taken along line III-III′ inFIG. 5.

Referring to FIGS. 5 and 6, after the amorphous silicon pattern 122 andthe n⁺ amorphous silicon pattern 124 are formed on the substrate 100, asource/drain thin layer may be entirely formed on the substrate 100. Inalternative embodiments, the source/drain thin layer may be patterned bythe photolithography process using the mask. As a result, a data line130, a source electrode 132 and a drain electrode 134 may be formed onthe substrate 100.

The data line 130 may be extended along the second direction, and thesource electrode 132 may be extended from the data line 130 along thefirst direction as shown in FIG. 5. The data line 130 and the sourceelectrode 132 may be substantially perpendicular to each other.

In exemplary embodiments, the source electrode 132 extended from thedata line 130 may be electrically connected to one side of the n⁺amorphous silicon pattern 124. In alternative embodiments, the drainelectrode 134 may be electrically connected to another side of the n⁺amorphous silicon pattern 124.

Referring to FIG. 6, a protecting layer 140 may be formed on thesubstrate 100 to cover the data line 130, the source electrode 132 andthe drain electrode 134.

As described above, the gate line 110, the gate electrode 112, the n⁺amorphous silicon pattern 124, the amorphous silicon pattern 122, thedata line 130, the source electrode 132 and the drain electrode 134 maybw formed on the substrate 100 using multiplemasks. In alternativeembodiments, the gate line 110 and the gate electrode 112 may be formedusing one mask. In other alternative embodiments, the n⁺ amorphoussilicon pattern 124, the amorphous silicon pattern 122, the data line130, the source electrode 132 and the drain electrode 134 may be formedusing one mask.

FIG. 7 is a plan view of an exemplary embodiment of a photoresistpattern formed on a protecting layer. FIG. 8 is a cross-sectional viewtaken along line IV-IV′ in FIG. 7. FIG. 9 is an enlarged viewillustrating an exemplary embodiment of portion ‘A’ in FIG. 8.

Referring to FIGS. 7 through 9, the photoresist thin layer is entirelyformed on the substrate 100. The photoresist thin layer may be patternedusing the mask to form a photoresist pattern 150 on an upper face of thesubstrate 100. Reference number 150 a in FIGS. 7 and 8 indicates a pixelarea that may be exposed through an area from which the photoresistpattern 150 is removed.

The protecting layer 140 may be patterned using a photoresist pattern150 as the mask to form a protecting pattern 142 on the substrate 100.In exemplary embodiments, when the protecting pattern 142 is partiallyopened or entirely removed, the drain electrode 134 covered by theprotecting layer 140 may be exposed as shown in FIG. 8.

When the protecting layer 140 is patterned using the photoresist pattern150 as the mask, the protecting layer 140 may be isotropically etched bya wet etching. For example, as the protecting layer 140 is isotropicallyetched by the wet etching, the protecting pattern 142 is more etchedthan an edge portion of the photoresist pattern 150 to generate anundercut at the protecting pattern 142. As best shown in the enlargedview of portion ‘A’ in FIG. 9, reference numeral 142 a denotes theundercut.

In alternative embodiments, when the protecting layer 140 is patternedusing the photoresist pattern 150 as the mask, the protecting layer 140may be anisotropically etched by a dry etching. For example, after theprotecting layer 140 is anisotropically etched by the dry etching, theprotecting layer 140 may be isotropically etched by the wet etching togenerate the undercut 142 a at the protecting pattern 142.

FIG. 10 is a cross-sectional view of an exemplary embodiment of atransparent conductive thin layer formed on the substrate in FIG. 9.

Referring to FIG. 10, a transparent conductive material is deposited onthe substrate 100. The transparent conductive material may include, butis not limited to, indium zinc oxide (IZO). In alternative embodiments,the transparent conductive material may include amorphous indium tinoxide (a-ITO), indium tin oxide (ITO), and the like, as well ascombinations including at least one of the foregoing.

In exemplary embodiments, as the transparent conductive material isformed on the substrate 100, a conductive layer 160 may be formed on thephotoresist pattern 150. As shown in the exemplary embodiment of FIG.10, a pixel electrode 170 is formed on the gate insulating layer 114,and the pixel electrode 170 is electrically separated from theconductive layer 160 since the undercut 142 a is formed between theconductive layer 160 and the pixel electrode 170.

FIG. 11 is a cross-sectional view of an exemplary embodiment of thesubstrate in FIG. 10 with a part of a photoresist pattern and aconductive layer removed.

Referring to FIG. 11, after the conductive layer 160 and the pixelelectrode 170 are formed on the substrate 100, a stripping composition184 may bes sprayed on the substrate 100 through, for example, adispenser 182.

In exemplary embodiments, the stripping composition 184 may include astripping agent for the photoresist layer and a stripping additive forthe conductive layer. For example, the stripping agent for thephotoresist layer may react with the photoresist pattern 150 to removethe photoresist pattern 150. In alternative embodiments, the strippingadditive for the conductive layer may etch the conductive layer 160.

The stripping composition may include as the stripping agent for thephotoresist layer, an amine-based compound, a protonated glycol-basedcompound, a deprotonated multipolar compound, and the like, as well asany combination including at least one of the fore going. The strippingadditive for the conductive layer may include, but is not limited to athiol-based compound, an oxalic acid derivative.

The stripping composition will be later described in detail.

In exemplary embodiments, the stripping composition may strip thephotoresist pattern 150, remove the conductive layer 160, and etch thepixel electrode 170 since the stripping composition may include thestripping agent for the photoresist layer and the stripping additive forthe conductive layer.

Referring to FIG. 11, when the stripping composition 184 is sprayed onthe photoresist pattern 150, the conductive layer 160 and the pixelelectrode 170 formed on the photoresist pattern 150, even the conductivelayer 160 and the pixel electrode 170 may be etched by the strippingcomposition while the photoresist pattern 150 is stripped.

The photoresist pattern 150 may be primarily stripped, and then theconductive layer 160 and the pixel electrode 170 may be etched.Advantageously, stripping time for stripping the photoresist pattern 150may be properly controlled.

A required time for removing the conductive layer 160, formed on thephotoresist pattern 150, from the substrate 100 by stripping thephotoresist pattern 150 using the stripping composition 184 may bedefined as a first time. A required time for completely etching theconductive layer 160 and the pixel electrode 170 using the strippingcomposition 184 is defined as a second time. The first and second timesmay be defined by a relationship represented by Formula 1.The first time<The second time  [Formula 1]

The stripping composition 184 is sprayed on the substrate 100 toseparate the conductive layer 160 from the substrate 100 within thefirst time, so that the pixel electrode 170 is essentially preventedfrom being damaged by the stripping composition 184. In exemplaryembodiments, the first time may range from about 2 minutes to about 4minutes when the stripping composition described above is used. Inalternative embodiments, the first time may preferably range from about2.5 minutes to about 3 minutes.

The parts of the conductive layer 160 separated from the substrate 100after applying the stripping composition 184 are flowed into a storagetank 186 with residual stripping composition 184. The separatedconductive layer 160 that flows into the storage tank 186 with theresidual stripping composition 184 may be completely dissolved withinthe second time. In exemplary embodiments, the second time may rangefrom about 10 minutes to about 30 minutes when the stripping composition184 described above is used.

In alternative embodiments, when the separated conductive layer 160 iscompletely dissolved in the storage tank 186, the stripping composition184 may be recycled to be provided again to the dispenser 182. Forexample, the stripping composition 184 may be repeatedly used in afollow-up process.

In exemplary embodiments, the photoresist pattern 150 may be stripped ata temperature ranging from about 60° C. to about 80° C., and theconductive layer 160 may be dissolved at a temperature ranging fromabout 60° C. to about 80° C.

FIG. 12 is a cross-sectional view of an exemplary embodiment of a thinfilm substrate without the photoresist pattern and the conductive layerin FIG. 11.

Referring to FIG. 12, the photoresist pattern 150 may be stripped by thestripping composition 184, and parts of the conductive layer 160 may beseparated from the substrate 100 to be flowed into the storage tank 186.Advantageously, a thin film transistor and the pixel electrode 170remain on the substrate 100. In exemplary embodiments, the substrate 100may be preferably cleaned to effectively prevent the pixel electrode 170from being damaged by the stripping composition 184 remaining on thesubstrate 100.

An Exemplary Embodiment of a Stripping Composition

An exemplary embodiment of a stripping composition will be described indetail hereinafter.

As discussed earlier, the stripping composition may include a strippingagent for a photoresist layer and a stripping additive for a conductivelayer. In exemplary embodiments, the stripping agent for the photoresistlayer may strip a photoresist pattern, and the stripping additive forthe conductive layer may etch the conductive layer. The stripping agentfor the photoresist layer may include an amine-based compound, aprotonated glycol-based compound, a deprotonated multipolar compound andthe like, as well as any combination including at least one of theforegoing. The stripping additive for the conductive layer may include athiol-based compound.

Examples of the amine-based compound may include, but are not limitedto, mono ethanol amine, mono isopropanol amine, methylmethanol amine,ethylethanol amine, dimethanol amine, aminoethoxyethanol amine and thelike. These compounds may be used alone or in a mixture thereof.

In exemplary embodiments, when a content of the amine-based compound isless than about 20 percent by weight, the photoresist pattern may not besufficiently stripped in a period of time. In other exemplaryembodiments, when the content of the amine-based compound exceeds about40 percent by weight, a pixel electrode may be excessively etched and/orbe damaged while the photoresist pattern is stripped. Further, when thecontent of the amine-based compound exceeds about 40 percent by weight,an amount of evaporated stripping composition 184 may increase to changethe contents of components in the stripping composition 184.

In alternative embodiments, where the photoresist pattern may besufficiently stripped and/or the pixel electrode may not be excessivelyetched or damaged, the content of the stripping composition ranges fromabout 20 percent by weight to about 40 percent by weight. In otheralternative embodiments, the content of the stripping composition maypreferably range from about 25 percent by weight to about 35 percent byweight.

Examples of the protonated glycol-based compound may include, but arenot limited to, butyldiglycol, diethyleneglycol methylether,diethyleneglycol ethylether, diethyleneglycol propylether,diethyleneglycol butylether, ethyleneglycol, and the like. Thesecompounds may be used alone or in a mixture thereof.

In exemplary embodiments, when a content of the protonated glycol-basedcompound is less than about 20 percent by weight, dissolution of thephotoresist layer may excessively decrease. In other exemplaryembodiments, when the content of the protonated glycol-based compoundexceeds about 50 percent by weight, sediment may be generated. Inalternative embodiments where the photoresist layer dissolution may notessentially decrease excessively and/or no sediment may effectivelygenerated, the content of the protonated glycol-based compound may rangefrom about 20 percent by weight to about 50 percent by weight.

Examples of the deprotonated multipolar compound may include, but arenot limited to, N-methyl-2-pyrrolidone, N,N-dimethyl acetamide,N,N-dimethyl formamide, N,N-dimethyl imidazole, and the like. Thesecompounds may be used alone or in a mixture thereof.

In exemplary embodiments, when a content of the deprotonated multipolarcompound is less than about 20 percent by weight, stripping time of thephotoresist pattern may increase, thereby inducing a damage of theconductive layer. Here, the damage may be caused by thiol-basedcompound. In other exemplary embodiments, when the content of thedeprotonated multipolar compound exceeds about 40 percent by weight, theconductive layer may be etched while etching the photoresist pattern. Inalternative embodiments, when the stripping time of the photoresistpattern may not effectively increase and/or the conductive layer may beessentially undamaged and/or unetched, the content of the deprotonatedmultipolar compound may range from about 20 percent by weight to about40 percent by weight. In alternative embodiments, the content of thedeprotonated multipolar compound may preferably range from about 25percent by weight to about 35 percent by weight.

In alternative embodiments, the stripping additive may include athiol-based compound or an oxalic acid derivative. In other alternativeembodiments, the thiol-based compound may preferable to the oxalic acidderivative. Examples of the thiol-based compound may include, but arenot limited to, a thiobenzoic acid, thiol acid, and the like. Thesecompounds may be used alone or in a mixture thereof.

In exemplary embodiments, when a content of the thiol-based compound isless than about 0.5 percent by weight, the conductive layer may not becompletely dissolved in the stripping composition, such that recyclingof the stripping composition may be difficult. In other exemplaryembodiments, when the content of the thiol-based compound exceeds about3 percent by weight, sediment may be generated in the strippingcomposition. In alternative embodiments, the content of the thiol-basedcompound may range from about 0.5 percent by weight to about 3 percentby weight. In other alternative embodiments, when the conductive layerlay essentially be dissolved and/or no sediment is effectivelygenerated, the content of the thiol-based compound may preferably rangefrom about 1.5 percent by weight to about 2 percents by weight.

Hereinafter, an exemplary embodiment of the present invention isdescribed in detail with reference to the following examples. Theexamples are given solely for the purpose of illustration and are not tobe construed as limitations of the present invention, as many variationsthereof are possible without departing from the spirit and scope of theinvention.

EXAMPLES 1 to 3

About 100 ml of a stripping composition was acquired according to acomposition of Table 1.

TABLE 1 Composition (percents by weight) Amine- based ProtonatedDeprotonated Thiol- compound glycol-based multipolar based Monoeth-compound compound compound anol Butyldi- Ethylene- N-methyl-2- ThiolExample amine glycol glycol pyrrolidone acid Example 1 30 25 14 30 1Example 2 30 25 13.5 30 1.5 Example 3 30 25 13 30 2Experiment 1: Estimation of Solvating Power of an IZO Conductive Layer

Each of the stripping compositions of Examples 1, 2 and 3 was heated toa temperature of about 70° C., and then the heated strippingcompositions were added to an indium zinc oxide (IZO) layer (550 Å) andkept for about 30 minutes. Then, dissolution of the conductive layer wasobserved.

FIG. 13A is a picture of a surface of the conductive layer dissolved byan exemplary embodiment of a stripping composition of Example 1. FIG.13B is a picture of a surface of the conductive layer dissolved by anexemplary embodiment of a stripping composition of Example 2. FIG. 13Cis a picture of a surface of the conductive layer dissolved by anexemplary embodiment of a stripping composition of Example 3.

Referring to FIGS. 13A to 13C, the IZO layer is shown completelydissolved within about 30 minutes of the addition of the heatedstripping compounds. Advantageously, the stripping composition maycompletely dissolve the conductive layer within about 30 minutes of aprocessing time.

Experiment 2: Measuring an Eluted Amount of Indium and Zinc

Each of the stripping compositions of Examples 1 and 3 was sprayed onthe thin film transistor substrate after the photoresist pattern wascompletely stripped. Eluted amounts of indium and zinc were respectivelymeasured. Results are shown in Table 2. The stripping composition ofExample 3 was sprayed on the thin film transistor substrate before thephotoresist pattern was stripped, then the eluted amounts of indium andzinc were respectively measured. Results are shown in Table 3.

TABLE 2 After PR stripping 3 minutes 10 minutes 30 minutes Metal Example(ppb) (ppb) (ppb) Indium Example 1 16.2 68.9 230.1 Example 3 20.7 95.2291.5 Zinc Example 1 2.4 4.6 9.8 Example 3 3.4 4.2 15.7

TABLE 3 Before PR stripping 3 minutes 10 minutes 30 minutes MetalExample (ppb) (ppb) (ppb) Indium Example 3 125.2 206.8 358.2 ZincExample 3 11.9 16.4 20.7

Referring to Tables 3 and 4, the eluted amount of the metal after PRstripping shows a difference of about 100 ppb with respect to the elutedamount of the metal before PR stripping. Advantageously, the conductivelayer on the photoresist pattern is removed during the PR stripping.

Experiment 3: Variation of Content of Amine

About 1000 ml of PR stripper (commercially available as a trade name ofPRS-2000, manufactured by Dong-woo finechem Co., Korea) as a ComparativeExample and about 1000 ml of the stripping composition of Example 2 wereexhausted by forced exhaust (FE) type. Variation of the content of aminewas measured during the exhausting process. Results are shown in Table4.

TABLE 4 10 minutes 20 minutes 30 minutes 40 minutes (ml) (ml) (ml) (ml)Comparative 10 20 30 40.5 Example Example 4 7 10.5 14 15

Referring to Table 4, variation of the content of amine in the strippingcomposition of Example 4 was lower than variation of the content ofamine in the stripper of Comparative Example. Advantageously, thestripping composition according to an exemplary embodiment of thepresent invention may have an excellent stability.

As discussed above, the exemplary embodiments of a method ofmanufacturing a thin film transistor substrate may improve an efficiencyof manufacturing process for the thin film transistor substrate.

Further, the exemplary embodiments of the stripping composition used forthe manufacturing process of thin film transistor substrate discussedabove, may dissolve the photoresist and/or the conductive layer.Advantageously, solid components may not remain in the used strippingcomposition, such that the used stripping composition may be recycledand reused in the process of manufacturing the follow-up thin filmtransistor substrate. As a further advantage, the stripping compositionmay have the excellent stability.

1. A method of manufacturing a thin film transistor substratecomprising: forming a gate line and a gate electrode on a substrate;forming a gate insulating layer and an active layer on the gate line andthe gate electrode; forming an active pattern; forming a data line, asource electrode and a drain electrode on the substrate, the forming adata line, a source electrode and a drain electrode including depositinga data metal layer on the substrate on which the active pattern isformed and patterning the data metal layer; forming a protecting layeron the substrate to cover the data line, the source electrode and thedrain electrode; forming a photoresist pattern and a pixel area on thesubstrate, the photoresist pattern being formed on the protecting layer;overetching the protecting layer using the photoresist pattern as a maskto form an undercut at a lower portion of the photoresist pattern;depositing a conductive material on the photoresist pattern and thepixel area to form a conductive layer and a pixel electrode on thesubstrate, the conductive layer being separated from the pixelelectrode; applying a stripping composition onto the substrate to stripthe photoresist pattern and/or remove the conductive layer formed on thephotoresist pattern from the substrate; and collecting used strippingcomposition, the used stripping composition including the conductivelayer removed from the substrate and completely dissolved in the usedstripping composition.
 2. The method of manufacturing a thin filmtransistor substrate according to claim 1, further comprising cleaningthe stripping composition remaining on the substrate.
 3. The method ofmanufacturing a thin film transistor substrate according to claim 1,wherein the used stripping in composition is stored in a storage tank.4. The method of manufacturing a thin film transistor substrateaccording to claim 1, wherein the stripping composition comprises astripping agent for a photoresist layer and a stripping additive for aconductive layer, the stripping agent for the photoresist comprising:about 20 percent by weight to about 40 percent by weight of anamine-based compound; about 20 percents by weight to about 50 percent byweight of a protonated glycol-based compound; and about 20 percent byweight to about 40 percent by weight of a deprotonated multipolarcompound, and the stripping additive for the conductive layer comprisingabout 0.5 percent by weight to about 3 percent by weight of athiol-based compound.
 5. The method of manufacturing a thin filmtransistor substrate according to claim 4, wherein the conductive layeris dissolved for about 10 minutes to about 30 minutes.
 6. The method ofmanufacturing a thin film transistor substrate according to claim 4,wherein the pixel electrode and the conductive layer comprise indiumzinc oxide (IZO), indium tin oxide (ITO), amorphous indium tin oxide(a-ITO) or any combination including at least one of the foregoing. 7.The method of manufacturing a thin film transistor substrate accordingto claim 1, wherein the used stripping composition is recycled andcontinuously used for the manufacturing of subsequent thin filmtransistor substrate.
 8. A method of manufacturing a thin filmtransistor substrate comprising: forming a gate line and a gateelectrode on a substrate; forming a gate insulating layer and an activelayer on the gate line and the gate electrode; forming a data metalpattern and an active pattern by using single mask, the data metalpattern including a data line, a source electrode and a drain electrode;forming a protecting layer on the substrate to cover the data line, thesource electrode and the drain electrode; forming a photoresist patternand a pixel area on the substrate, the photoresist pattern being formedon the protecting layer; overetching the protecting layer using thephotoresist pattern as a mask to form an undercut at a lower portion ofthe photoresist pattern; depositing a conductive material on thephotoresist pattern and the pixel area to form a conductive layer and apixel electrode on the substrate, the conductive layer being separatedfrom the pixel electrode; applying a stripping composition onto thesubstrate to strip the photoresist pattern and/or remove the conductivelayer formed on the photoresist pattern from the substrate; andcollecting used stripping composition, the used stripping compositionincluding the conductive layer removed from the substrate and completelydissolved in the used stripping composition.
 9. The method ofmanufacturing a thin film transistor substrate according to claim 8,further comprising cleaning the stripping composition remaining on thesubstrate.
 10. The method of manufacturing a thin film transistorsubstrate according to claim 8, wherein the used stripping incomposition is stored in a storage tank.
 11. The method of manufacturinga thin film transistor substrate according to claim 8, wherein thestripping composition comprises a stripping agent for a photoresistlayer and a stripping additive for a conductive layer, the strippingagent for the photoresist comprising: about 20 percent by weight toabout 40 percent by weight of an amine-based compound; about 20 percentsby weight to about 50 percent by weight of a protonated glycol-basedcompound; and about 20 percent by weight to about 40 percent by weightof a deprotonated multipolar compound, and the stripping additive forthe conductive layer comprising about 0.5 percent by weight to about 3percent by weight of a thiol-based compound.
 12. The method ofmanufacturing a thin film transistor substrate according to claim 11,wherein the conductive layer is dissolved for about 10 minutes to about30 minutes.
 13. The method of manufacturing a thin film transistorsubstrate according to claim 11, wherein the pixel electrode and theconductive layer comprise indium zinc oxide (IZO), indium tin oxide(ITO), amorphous indium tin oxide (a-ITO) or any combination includingat least one of the foregoing.
 14. The method of manufacturing a thinfilm transistor substrate according to claim 8, wherein the usedstripping composition is recycled and continuously used for themanufacturing of subsequent thin film transistor substrate.